3-month Chess King LEARN subscription, giving access to all courses available there (60 as of Nov.2017 and counting)! The courses are available in 9 European languages, sorted by category and difficulty level, and include such gems as Chess Tactics for Beginners 2.0, Chess: From Beginner to Club Player, Chess Strategy, Chess Middlegame series, several courses from CT-ART and Chess Tactics in the Opening series and more.
Updated databases now contain 6.8 million games in total!
1-year access to Lomonosov Tablebases! The subscription will be active for 1 year starting the date of activation at the tablebases service.

If you already own the Houdini 6 UCI engine and are looking for an appropriate interface, ChessOK Aquarium 2018 is the best you can find.

Interactive Deep Analysis is the the most advanced chess analysis method available today.

Infinite Analysis is more flexible than ever with analysis presets.

Find Blunders and Game Analysis for analyzing whole games.

You receive 1-year access to 7-piece Lomonosov endgame tablebases via the Aquarium interface or at tb7.chessok.com.

You also receive 3-month access to all courses at Chess King Learn. The collection includes courses on all topics and for all levels of play. Use your product key as a promo code to activate the subscription. (How to activate Chess King Learn bonus subscription)

ChessOK Aquarium 2018 can auto-find chess programs (including the strong Stockfish 8 engine) on the Internet, download and install them - all in a couple of clicks.

Play against the computer. Choose from three different strength handicap methods, material handicap or time handicap. You can also just set the ELO level you want to play against!

Publish your games, analyses or even whole chess books! Publish as Aquarium iBook, on the web/blog or in print.

Compatibility with major opening book and database formats.

Databases of about 6.8 million games in total (up to November 2, 2017) that can be updated from www.chessok.com each week with 1500 new games for free.